Pi Chamaeleontis

π Chamaeleontis
Observation data
Epoch J2000      Equinox J2000
Constellation Chamaeleon
Right ascension 11h 37m 15.63631s[1]
Declination −75° 53′ 47.5626″[1]
Apparent magnitude (V) 5.64[2]
Characteristics
Spectral type A9 IV[3] or F1 III[4]
U−B color index −0.01[5]
B−V color index +0.35[5]
Astrometry
Radial velocity (Rv)−9.8±3.7[6] km/s
Proper motion (μ) RA: −127.94[1] mas/yr
Dec.: −1.82[1] mas/yr
Parallax (π)24.09 ± 0.33 mas[1]
Distance135 ± 2 ly
(41.5 ± 0.6 pc)
Absolute magnitude (MV)2.56[7]
Orbit[1]
Period (P)223.1845±1.9460 d
Semi-major axis (a)7.86±0.83 mas
Eccentricity (e)0.3244±0.1375
Inclination (i)104.88±5.52°
Details
Mass1.52[8] M☉
Radius2.2[9] R☉
Luminosity8[9] L☉
Surface gravity (log g)4.08[8] cgs
Temperature6,853±80[6] K
Metallicity [Fe/H]−0.28[6] dex
Rotational velocity (v sin i)50[10] km/s
Age1.8±0.1[7] Gyr
Other designations
π Cha, CPD−75°744, FK5 438, HD 101132, HIP 56675, HR 4479, SAO 256857[11]
Database references
SIMBADdata

Pi Chamaeleontis, its name Latinized from π Chamaeleontis, is a binary star[12][13] system located in the southern circumpolar constellation of Chamaeleon. It is dimly visible to the naked eye with an apparent visual magnitude of 5.64.[2] Parallax measurements by Hipparcos put the system approximately 135 light-years (41.5 parsecs) away.[1] It is drifting closer with a radial velocity of −10 km/s.[6]

The Hipparcos satellite mission derived a 223 d orbit on the basis of its motion caused by an unseen companion.[1] The visible component is an A-type subgiant[3] or F-type giant star with an effective temperature of about 6,900 K.[6] It has an absolute magnitude of 2.56,[7] a mass of 1.52 M☉,[8] and a radius of 2.2 M☉.[9] It is roughly 1.8 billion years old.[7]

  1. ^ a b c d e f g h Cite error: The named reference HIP was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference AllendePrieto was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk1975 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Kharchenko was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Johnson was invoked but never defined (see the help page).
  6. ^ a b c d e Cite error: The named reference Casagrande was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Holmberg was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference Lambert was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference Chandler was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Balachandran was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Eggleton_Tokovinin_2008 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Bartkevicius_Gudas_2001 was invoked but never defined (see the help page).